40 HOUGH'S AMERICAN WOODS. 



macerating the fresh bark or fruit in brandy, is a popular remedy in 

 chronic rheumatism.* 



NOTE. A very thin longitudinal section of this timber, looked 

 through in the dark toward a lighted lamp, shows an interesting and 

 pretty phenomenon. As it is held with the grain horizontal, there is 

 seen to the right and left of the light or the lighted point directly in 

 range with the light a display of the prismatic colors, which is quite 

 brilliant and beautiful. They seem like miniature sundogs, and there 

 are two or three of them on each side of the light, those nearest being 

 brightest. 



A microscopic examination reveals the cause of this interesting appear- 

 ance. The wood is found to be copiously supplied with spiral ducts, i. e., 

 ducts whose walls are marked with a spiral thickening (See 11, p. 2). 

 These spirals are so small that their coils would number several thousand 

 to the inch. They can be distinctly traced by varying the focus of the 

 instrument; but, at a certain focus, where only one side of the spiral can 

 be seen, they seem like rows of parallel crystals or prisms, and it is by 

 these that the light is refracted, causing the display of colors quite as the 

 crystals of frost in the air in winter cause the colors in the sundogs. 



GENUS LIRIODENDRON, L. 



Leaves folded crosswise in the bud, each infolding all that is interior to it, and is 

 itself infolded by its pair of stipules and the next lower leaf, and so on; buds flat, 

 the large, sheathing, oval stipules caducous. Flowers showy, with 3 reflected cadu- 

 cous sepals, and 6 erect petals in two rows, making a bell-shaped corolla; anthers 

 linear, opening outward; carpels flat, scale-like, long and narrow, imbricating and 

 cohering together in an elongated dry cone, separating at maturity and falling away 

 whole as samarae, somewhat lanceolate in shape and each bearing 1-2 seeds in its 

 base, indehiscent. 



Trees of fine aspect. (Name from the Gk. X.Eipiov, lily, and devdpov, tree.} 



2. LIRIODENDRON TULIPIFERA, L. 



TULIP TREE, WHITE-WOOD, WHITE OR YELLOW " POPLAR," CANOE- 

 WOOD. 



Ger., Tulpenbaum; Fr., Tulipier; Sp., Tulip if 'ero. 



SPECIFIC CHARACTERS : Leaves dark green, very smooth and shining, truncate, 

 with two spreading lobes separated by a broad, shallow sinus at the apex, and with 

 two lateral lobes near the base, 3-5 in. (8-13 cm.) in length and of about the same 

 width, long petioles. Flowers (May, June) solitary, erect, more bell-shaped than the 

 common garden tulip, greenish yellow marked with orange. Fruit (September) a 

 greenish cone 2-3 inch. (5-8 cm.) in length, the scales of which in reality so many 

 samerse persisting long after the leaves have fallen, and then more or less spread- 

 ing and bleached nearly white, give the tree in winter a very characteristic 

 appearance. 



(Tnlipifera from Persian toulyban, a turban whence from resemblance in the flower 

 the Eng. " tulip " and Lat. fero, I bear.} 



*U. S. Dispensatory, 15th ed., pp. 916-917. 



